practices/a.c

/* Demonstrate basic macro expansion behaviours, particularly the ability to expand twice.
 *
 * Compile with gcc -Wall -g -o a a.c
 * Execute with ./a
 */
#include <stdio.h>
#define A B
#define B printf

#define C(a,b,c) D("hello %d\n",b,c)
#define D(x,y,z) do { \
	printf(x, y+z); \
} while(0)

int main(int argc, char *argv[]) {
	A("hello world\n");
	C(0, 3, 4);
	return 0;
}